Method of forming a multilayered mat of intercrossed filaments



NOV. 6, 1951 p MOD|GL|AN| 2,574,221

METHOD OF FORMING A MULTILAYERED MAT OF INTERCROSSED FILAMENTS Flled March 16, 1946 77047/VEY.

Patented Nov. 6, 1951 METHOD 0F FORMING A MULTILAYERED MAT OF INTERCROSSED FILAMENTS Piero Modigliani, Manhasset, N. Y., assignor to Johns-Manville Corporation, New York, N. Y., a corporation of New York Application March 16, 1946, Serial No. 654,828

5 Claims. (Cl. 154-90) accumulated on a rotating drum. 'I'he furnace i laments of each of the layers accumulated on the drum are crossed suitably at acute angles to the filaments of adjacent layers. When the mat is built up to the desired thickness it is removed lfrom the drum and stretched in a direction substantially perpendicular to the original lay of the filaments, whereby the mat is expanded or opened in a manner similar to that of a lazy.

tongs, the angles between the fibers opening to increase the porosity and to reduce the density and thickness of the mat. The resultant mat has been employed both with and without the addition of an adhesive binder for many purposes.

The instant invention is particularly concerned with the provision of an improved mat which will have high strength and stretch-resistant characteristics in all directions. 'I'he invention also has for an object the provision of a mat with a. glossy and more attractive surface than the mats heretofore obtained, the surfacebeing subject to ornamentation. The mat may be used in many situations Where the prior mats are not wholly successful, due to their surface characteristics, stretchability or other undesirable features eliminated by the instant construction. 'l y Another object of the invention is the provision of a product including an expanded base mat or layer and a finish mat or layer on one surface of the base, the mats being integrated into a substantially unitary body.

A further object `of the invention is the provision of a methodv of forming a product of a type attaining the foregoing objects.

A still further object of the invention is the provision of a method involving the production of an expanded mat and the accumulation on said mat of a fllamentary surface layer in which the'filaments lie approximately transversely vto the fibers of the first mat.

`A still further obiect of the invention is the provision of a method employing a filamentdrawing apparatus such as a rotating drum of -and drum are relatively reciprocated so that the l 2 substantially conventional typeas a support for the first mat while the second mat is built up thereon.

My invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the more detailed description of a preferred embodiment of the invention which is to follow and to the accompanying drawing in which:

Fig. 1 is a perspective view of a product of the instant invention;

Fig. 2 is' a diagrammatic, elevational view of a portion of an apparatus employed in producing .the product of Fig. 1;

Fig.' 3 is a sectional view taken on the line 3-3 of Fig. 2; n

Fig. 4 is a diagrammatic, perspective view of a mat of intercrossed glass filaments as employed in the instant invention and illustrating the condition of the mat before and after stretching operations;

Fig. 5 is' a diagrammatic, end view ofv additional equipment employed in the production of the instant product; and,

Fig 6 is a top plan view of the apparatus shown in Fig. 5.

Referring now to the drawings and particularly to Fig. 1, the product of the instant invention includes a base layer or mat l0 composed of intercrossed, continuous or substantially continuous fine filaments I2. The mat is of preferably open, reticulated structure with the filaments crossing each other at approximately right angles to one another. Preferably fine glass filaments of a diameter range, say, between 6 and 18 microns make up the mats, although filaments of other sizes and/or other fusible materials may be employed. The filaments of mat I0 may be bound together by a suitable adhesive or binder as, for example, a water-soluble, thermo-setting resin, i. e., phenol-formaldehyde. urea formaldehyde or the like. or a hinder such as gelatin. Water insoluble binders of any suitable type, such as polyvinyl alcohols. acryol, etc., or combinations of water-soluble and water insoluble binders may be employed. The binder is used in minor proportions, say, from 2-25% by weight of the mat, and is preferably disseminated substantially uniformly throughout the mat.

Qverlying layer I 0 is a second filamentary' layer H also 'composed of substantially'continuous filaments, suitably of the same kind 'employed in mat I0. The filaments I8 of this layer extendapproximately transversely to the filaments of mat Il and are preferably in substantial parallelism. Filaments il are bound to each other and mats Il and il are bound into a substantially integral product by an adhesive binder which may be of the same type as used in the formation of mat il. However, the binders need not be the same in both mats, nor do the binders for either of the mats need to be selected from those specifically referred to, as any other adhesives having the properties desired for `a particular service may be employed.

Filaments i2 and I6 are drawn from a fusible material, such as a glass melt, and in the manner fully explained below. Although the mats Il and Il have been referred to in some instances as layers. it will be understood that each is made up of a plurality of laps or laminations of the glass filaments to produce a body of appreciable thickness. Also, although the nlamenis of mat I4 preferably all' lie in approximate parallelism, this is not critical and they may also intercross to a substantial extent. as long as they extend approximately transversely to the lay of the bers in mat i0.

Surface layer or mat Il, particularly when the fibers are in substantial parallelism as in the preferred construction provides a glossy, lightreflective surface which adapts the product for use as a decorative medium and for other purposes for which the expanded mat Iii alone is I not suitable. The glossy, light-reflective surface of the product may be printed or otherwise decorated and also mat Il may be colored as desired.

Referring now particularly to Figs. 2-6, the method of forming the product described above will be explained in detail. Mat III is preferably fabricated by following substantially the conventional practice as described, for example, in my said Patent #2,081,060. In Figs. 2 and 3, there is diagrammatically shown a filament accumulating or drawing drum Il of the type employed in the patented method. The fiber integrally connected to glass issuing through the spinning orifices of a glass furnace 2l of any suitable type is brought into contact with the drum and continuously drawn directly from the glass furnace by rotation of the drum in the direction indicated by the arrow. Furnace 20 is reclprocated relatively to the drum, as indicated by the double-headed arrow in Fig. 3, to lay the glass filaments onto the drum in a plurality of layers of continuous spirals. withthe filaments of each layer crossing the filaments of adjacent layers. When the mat is built up to the desired thickness on drum Il, it is removed, suitably by slitting it axially of the drum, and is transferred to a conveyor or the like 22 which feeds it to a stretching device, indicated generally at Il. The stretching device may be of the type shown, for example, in my said Patent #2,081,060, but preferably an apparatus of the type 'described and claimed in the co-pending application of Robert E. Slack et al., S. N. 606,247, filed July 20, 1945, now Patent No. 2,486,217, is employed to secure a superior product.

Referring particularly to Fig. 4, the effect of the stretching operation is diagrammatically illustrated. The mat, as received from the drum. conventionally referred to at this stage as a condensed mat," is indicated by the reference character 26 and, after the strecthing operation. is indicated by the reference character 2l. As shown, the angular relationship between the fibers is altered as the mat is drawn or stretched. to produce a thinner, more open, reticulated structure.

adhesive is set and hardened. A section 33,-in-

dicated by the dot-dash lines Il of Fig. 4, is then cut from the mat, the section being of a length a equal to the circumference of a fiber-drawing or accumulator drum which may be drum Il employed for the original ber-drawing operation or which may be a separate, but preferably similar drum as shown at 38 in Figs. 5 and 8. Section I3 is wrapped onto the drum with its longitudinal dimension a extending circumferentially of the drum and secured by connecting the end edges with strips of adhesive tape or the like 3l. Drum 3l is then rotated and filaments II drawn from a glass furnace (not shown) which may be furnace 2l or one similar in all respects to furnace 2l, and the drawn filaments wrapped on the drum to overlie mat Il and form a surfacing layer or mat thereon. The fiber drawing is continued to wind a plurality of laps or layers of the laments to build up a mat of the desired thickness. Suitably the reciprocation of the furnace or of the drum, as the case may be, is relatively slow to lay the filaments of the second laps or layers in substantial parallelism, with the filaments extending approximately at right angles to the axis of the drum. However, the rate of reciprocation may be such as to lay the filaments in layers at acute angles to adjacent layers, similarly as in the formation of the original mat on the drum II but the more parallel accumulation of the filaments is preferred, as previously pointed out.

An adhesive or binder such as a water-soluble resin or gelatin, or a combination of watersoluble binders and water-insoluble binders. as referred to above, is sprayed onto the filaments or onto the mat of laments as the filaments are accumulated. For this purpose a spray device Il is located adjacent the point of wrapping of the filaments on the drum. The spray device may be of any suitable type comprising, for example, a pipe extending longitudinally of the drum, the pipe being connected to any suitable binder supply. The pipe is provided with a plurality of nozzles directed toward the drum. 'I'he ports or nozzles are relatively small to spray the binder against the drum in finely-divided or atomiaed form.

Drying means are employed to set the binder as the mat I 4 is accumulated on the drum. Such drying means, indicated generally at l2. may be of any suitable or'conventional type such as a battery of infra-red ray lamps. gas burners or the like. The drying means serves to set up the adhesive so that the combined product, when the mat I4 is built up to the desired thickness, may be directly removed from the drum. After removal, the mat is divided into segments of the selected size for the particular use for which the product is intended.

If desired a coloring material such as any of the known coloring compositions may be sprayed onto the mat I l during its formation to insure uniform depth of color of the surfacing layer. The coloring material may be included with the binder or may be supplied by a separate spray device.' indicated at 44.

The method described above provides a simple. effective and economical way of producing the product as shown in Fig. 1. 'I'he product may be varied in a number of particulars without the necessity of making major adjustments in the method or apparatus by which it is produced. The mat I may be expanded to any extent desired, within the limits permitted by the character of the material, during the stretching operation to provide a base mat of greater or lesser porosity, thickness and strength by merely properly adjusting the speed of the drawing mechanism. The surface mat may consist of substantially parallel fibers or of intercrossed fibers, by proper adjustment of the rate of traverse of the furnace relative to the drum during the accumulation of the mat on the base mat l0. Various colors may be employed in any suitable or desired arrangement.

Having thus described my invention in rather full detail, it will be understood that these details need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.

What I claim is:

1. The method comprising forming a multilayer mat of intercrossed filaments, stretching said mat, accumulating a second filamentary mat on said first mat with the filaments of said second mat extending generally in the direction of stretch of said first mat. and adhesively securing the second mat to the first mat.

l 2. The method comprising forming a multi- .layer mat of intercrossed filaments, stretching said mat, applying an adhesive to said stretched mat, accumulating a second filamentary mat on said first mat with the filaments of the second mat extending generally in the direction of stretch of the first mat, and applying an adhesive to said filaments of said second mat as they are accumulated.

3. The method comprising forming a multilayer mat of intercrossed fllaments, stretching said mat, applying an adhesive to said mat, placing said mat on a filament accumulating device, simultaneously drawing filaments from a raw material supply and collecting them on said mat, and applying adhesive to said flla- 5. The method comprising forming a filamen-`r tary mat having a plurality of coextensive layers with the filaments of each layer in substantial parallelism and in intercrossing relationship with the filaments of adjacent layers, stretching said mat to increase the angular relationship between the filaments of the layers and to produce a more open, reticulated structure, accumulating a second filamentary mat on said first mat with the filaments of said second mat extending generally longitudinally of the iirst mat and crossing the filaments thereof, and adhering the filaments of said mat together, and said second mat to said first mat.

PIERO MODIGLIANI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

1. THE METHOD COMPRISING FORMING A MULTILAYER MAT OF INTERCROSSED FILAMENTS, STRETCHING SAID MAT, ACCUMULATING A SECOND FILAMENTARY MAT ON SAID FIRST MAT WITH THE FILAMENTS OF SAID 